1. Field of the Invention
The present invention relates generally to a grounding unit of a folder type portable terminal, and in particular, to a portable terminal configured to have a variable-type grounding unit for performing variable ground operation in response to opening and closing of the folder, in order to prevent the degradation of antenna radiation from opening and closing of the folder.
2. Description of the Related Art
In recent years, the dramatic development of electronic communications has caused to be realized portable terminals that not only have a lightweight and small size, but also a large variety of functions that appeal to the consumer. For example, a speaker capable of outputting a melody with various harmonies i and a color display unit with a vast array of pixels are being implemented. In addition to the typical function of call communication, because such functions as listening to music via an MPEG audio layer-3 (MP3) player and a variety of game contents using the display unit are also being provided, there has been an increased concentration on the development of advanced functions.
Portable terminals are manufactured in a variety of types, which are generally classified according to their opening and closing operation for call communication. In particular, various types of terminals such as bar type, flip type, folder type, slide type, popup type and slide and rotation type terminals have been developed.
These portable terminals are equipped with an antenna module for portable wireless communication reception. Such an antenna module can be a built-in antenna module installed within the terminal as well as an external antenna module that protrudes from the terminal. Various efforts are made to show the best performance. Thus, the design and proper positioning of the antenna is of particular importance, for producing optimal performance of the terminal, especially when considering the variety of opening and closing operations in the various types of terminals.
For example, the folder type terminal can have an external antenna module protruding from the terminal or an antenna radiator installed in the terminal. Also, the folder type terminal can be configured such that its folder is electrically grounded to a hinge module opening at an angle from the body to improve the radiation of the antenna. The hinge module forms at least a hinge housing with metallic materials or forms inner components, such as a hinge shaft, a hinge cam operating by interlocking the hinge shaft, and a hinge spring that presses the hinge cam with metal materials, thereby performing ground operation.
However, the ground configuration for improving antenna radiation in the above conventional folder type terminal is designed for optimal antenna radiation performance in primarily an open folder state for call communication, along with some design consideration for the closed folder state. Thus, degradation of antenna radiation characteristic may occur in the closed folder state in which the folder of the terminal is constantly grounded to the hinge module.